qt-mcp

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states the tool captures an image, implying a read operation, but does not specify output format (e.g., PNG, JPEG), file handling (e.g., saved to disk or returned as data), permissions needed, or error conditions. For a tool with no annotation coverage, this leaves significant gaps in understanding its behavior.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is concise and well-structured: a clear purpose statement followed by a brief parameter explanation. It avoids unnecessary details and is front-loaded with the main function. However, it could be slightly more efficient by integrating the parameter note into the main sentence, but overall, it earns its place with minimal waste.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the complexity of capturing a VTK render window, no annotations, no output schema, and low schema coverage, the description is incomplete. It lacks information on output (e.g., image format, return value), error handling, dependencies on other tools (e.g., how to get 'ref'), and behavioral nuances. This makes it inadequate for an agent to use the tool effectively without additional context.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The description adds minimal semantics beyond the input schema: it explains that 'ref' is a 'Ref to a widget containing a VTK render window.' With 0% schema description coverage, this provides some context, but it does not detail the format of 'ref' (e.g., how to obtain it from other tools) or constraints. The baseline is 3 due to the single parameter, but the description only partially compensates for the lack of schema details.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool's purpose: 'Capture a VTK render window to an image.' It specifies the verb 'capture' and the resource 'VTK render window,' distinguishing it from generic screenshot tools like 'qt_screenshot' or 'qt_scene_snapshot' by focusing on VTK-specific rendering. However, it does not explicitly differentiate from all siblings (e.g., 'qt_vtk_scene_info' might be related), so it falls short of a perfect score.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides no guidance on when to use this tool versus alternatives. It mentions the parameter 'ref' but does not explain prerequisites, such as needing an active VTK widget, or compare it to similar tools like 'qt_screenshot' or 'qt_scene_snapshot.' Without any usage context or exclusions, the agent must infer when this tool is appropriate.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.